Strand handling apparatus



Patented Nov. 19, 1940 UNITED STATES 2,221,836 STRAND HANDLING-APPARATUS Edward L. Harold, Plainfield, N. J., assignor to Western Electric Company, Incorporated, New York, N. Y., a corporation of New York Application August 5, 1939, Serial No 288,648

12 Claims.

This invention relates to strand handling apparatus and more particularly to a device for stripping served cover strands from a core strand.

The combination of a substantially straight core strand with one or more sheathings thereon, each comprising one or more cover strands wound helically on the core or on an underlying sheath on the core, appears in a variety of arts put to innumerable uses. Particularly in the electrical arts are electrically conductive core strands having insulating sheathings of textile threads served thereon used in many ways and to an enormous extent. The sheathing of such conductor wires with threads served or helically wound thereon is done by the mile in a variety of machines designed for the purpose. In many cases it is necessary for the proper control of the process and product, to take sample lengths of the sheathed wire, pieces for example of a length of the order of three to six feet, and strip the served layer or layers of wound textile sheathing from the metal core for separate testing or for extraction of materials used to impregnate or color or otherwise treat the sheathed strand or for any one or more f a variety of product control examinations. It is a tedious, sometimes difficult, and always time wasting and therefore costly matter to unwind one, two, three .or even more layers of relatively fine threads by hand from a sample three to six foot length of insulated wire.

An object of the present invention is to provide a simple and durable device for stripping served cover strands from a core strand easily and swiftly.

One embodiment may comprise a pair of tubular members of internal diameter substantially greater than that of the served core to be stripped, positioned in mutual axial alignment with their mutually approximated spaced ends constricted to be only slightly larger in internal diameter than the served core to be stripped.

Other objects and features of the invention will appear from the following detailed description of one. embodiment thereof taken in connection with the accompanying drawings in which the same reference numerals are applied to identical parts in the several .figures and in which Fig. 1 is a broken plan view of a device embodying the invention;

Fig. 2 is an enlarged similar view of the middle portion thereof, and

of Fig.1.

In the embodiment of the invention herein disclosed a double base member Ill-l0, which may be laid orclamped on a table, bench or other suitable support for use, has the various parts of the device mounted thereon. The base, as shown, may conveniently consist of two bars l0, H] of wood, or of any other suitable material, linked together end to end by two connecting links II, II of metal or other suitable material, pivotally secured to the bars [0, In by bolts, pins or the like l2, l2. Thus the two bars with attached parts may be folded together for storage.

Tubes l4 and I5 are held in coaxial alignment on the upper surfaces of the bars ID by any appropriate means such as metal straps l6. Preferably the securing means are such that the tubes, while held against accidental displacement, may be adjusted longitudinally relatively to each other onthe bars. The mutually approximated ends l8 and IQ of the tubes are constricted as shown so that at these extremities the bores 20 and 2| of the tubes are reduced to apertures 22 and 23. Preferably the length of each of the tubes [4 and I5 isabout the same as the, length of the longest sample of served strand to be stripped in the device. Preferably also the diameters" of the bores 20 and 2| will be from two to eight times and the diameters of the apertures 22 and 23 from one and a quarter to three times the overall diameter of the sample to be stripped. However, the device will, in some instances, work satisfactorily with dimensions outside of the preferred limits.

An adjustable strand support 30 is mounted on one of the base members l0 substantially at the abutted junction thereof. This strand support, as shown, consists of a short section of angle ironslidably secured on the base member by screws 3| passing through a slot 32 in the horizontal arm of the support. The support, is so located that if a strand 40 of average overall diameter lie coaxially within the tubes l4 and IS the vertical arm 33 of the support 30 will be tangent to the surface of'the strand.

In operation the cover strands 4| are unwound by hand for an inch or so from one end 42 of a served strand 40. The other'end of the strand 40 is then fed back through the aperture 23 in the tube l5 until the bared end 42 can be inserted through the aperture 22 into the tube I4 as shown in Fig. 2. The free end of the strand or group of strands 4| is then grasped with'the fingers, pliers or other means, and pulled away from the axis of the device-as indicated by the straight arrow in Fig. 2. The device will operate most smoothly and simply if the strands El are drawn tangentially over the outer curved surface of the end 18 of the tube M as shown in Fig. 2 and in a direction at an acute angle to the core from which they are being stripped. The pull of the strands thus being stripped causes a rapid rotation about its axis of the covered part of the strand within the tube l5 and of the stripped part within the tube M, while the main also travels longitudinally from right to left from the tube It into the tube l4.

Were it not for the loose and unhindering conthe procedure impossibly unmanageable at any practically useful speed. lhe strand support arm 33, supporting the free part of the strand between the tubes against the pullof the stripping operation prevents this part of the strand from being centrifugally distorted.

It is believed to be generally preferable to provide and use thesupport 30 or its equivalent in the manner shown. However, if the core of the compound strand to be stripped is relatively stiff, and if the tubes H and 55 are adjusted to have their approximated ends relatively close together, the support 3@ maybe dispensed with entirely.

A prime essential of the preferred form of the device is the support of the stripped portion of the core near the stripping point 63 by the incurved endof the tube l4! which forms the rim of the aperture 22. The pull .of the cover strand naturally tends to bend the core over the rim of the aperture. This tendency is resisted by the support arm 33,.or, in the absence of this support, by the rim of the aperture 23. In either case, by suitable adjustment'of the tube ill. and the support 38, or, in the absence of the support 38, by suitable adjustment of. the two tubes, the points of support for the. rotating strand maybe brought near enough to the. stripping point so that no harmful or'troublesome bending" of the rotating strand takes place at the stripping point 43 between the two points of support. The allowable distances between the two points of support and. from either of these to the stripping point will depend largelynpon the inherent stiffnesses of the coveredstrand and of the stripped strand and upon the force required-to pull-off the cover strand atthe desired'speed.

The use of tubes with bores several times-larger than the overall diameter of the covered strand makes it possible inpractice: tostrip'sa'mples' of insulated wire having more or less permanent fiexures which would not pass through a long slender bore and which will pass through the short constrictions at the tube apertures. On the other hand. the tube bores should-not ordinarily be too great o'r'standing curves may. be formed in the rotating strand which will cause too great resistance toflongitudinal-pass'age of the strand through-the apertures.

The device will also function, although by no means as satisfactorily, if the approximated ends of the tubes be left square and not reduced or tapered as at laand [9, so that the'apertures 22 and 23 are the full widthof the bores. In such case, however, standingcurve's formed inthe ro tating strand tendto creep out of'the tubes (forward in i5 and backward in I l) and tend thus to force the stripping point to vibrate and the strand to bend and even kink suddenly at the stripping point.

Generally speaking, the softer and finer the core and the stiffer and heavier the cover strand, the more closely should the apertures 22 and 23 fit without impeding the rotating strand, and the more closely together should be the stripping point and the points of support. There are cases of a soft fine pure copper wire with a stiff wax impregnated textile serving where everything shown in Fig. 2 is necessary for practical working.

However, if a stifi, coarse hard wire is to be stripped of a soft cotton serving, the support 30 may be omitted and even the tapering down of the tube. ends also, and the device will function, although even then perhaps not at as high speed as the preferred form.

The invention is illustrated as stripping a served sheath of left hand pitch and stripping from left to right while the core moves from right to left. The device will work either way regardless of the direction of pitch of the serving. Hence, in the case of a core having two or more superimposed servings, the outer serving may be stripped as already described, and the next serving be removed by running in the opposite direction, and so on, without removing the strand from the device until all the successive served layers have been removed.

The illustrative embodiment of the invention herein disclosed may be modified and departed from in various ways also without departing from the spirit and scope of the invention as pointed out in and limited solely by the appended claims.

What is claimed is:

1. A device for stripping a helically served cover strand from a core strand which device comprises means to support a rotating strand from which a served cover strand is being pulled near the point of stripping, in combination with means to prevent the unstripped portion of the strandfrom harmful centrifugal distortion, and means to prevent the stripped portion of the strand from harmful centrifugal distortion.

2. A device for stripping a helically served cover strand from a core strand which device comprises means to support the stripped portion of a rotating strand from which a served cover strand is being pulled near the point of stripping, in combination with means to prevent the unstripped portion of thestrand from harmful centrifugal distortion, and means to preventthe stripped portion of the strand from harmful centrifugal distortion.

3. A device for stripping a helically served cover strand from a core strand which device comprises means to support the stripped portion of a rotating strand from which a served cover strand is being pulled near the point ofstripping, and means to support the unstripped portion of the rotating strand near the point of stripping, in combination withmeans to prevent the unstripped portion'of the strand from harmful centrifugal distortion, and means to prevent the stripped portion of the strand from harmful centrifugal distortion.

4; A device for stripping a helically served cover strand from a core strand which device comprises a tube to contain the stripped portion of a rotating strand from which a helically served cover strand is being pulled and to loosely constrain the same against harmful centrifugal distortion, and a second tube substantially incoa-Xial alignment with the first named tube tocontain the unstripped portion of the rotating strand and to loosely constrain the same against harmful centrifugal distortion.

5. A device for stripping a helically served cover strand from a core strand which device comprises a tube to contain the stripped portion of a rotating strand from which a helically served cover strand is being pulled and to loosely constrain the same against harmful centrifugal distortion, and a second tube substantially in coaxial alignment with the first named tube to contain the unstripped portion of: the rotating strand and to loosely constrain the same against harmful centrifugal distortion, aligned tubes being spaced apart and on opposite sides of the stripping point.

6. A device for stripping a helically served cover strand from a core strand which device comprises a tube to contain the stripped portion of a rotating strand from which a helically served cover strand is being pulled and to loosely constrain the same against harmful centrifugal distortion, and a second tube substantially in coaxial alignment with the first named tube to contain the unstripped portion of the rotating strand and to loosely constrain the same against harmful centrifugal distortion, in combination with a strand supporting member positioned between the two tubes.

7. A device for stripping a helically served cover strand from a core strand which device comprises a tube to contain the stripped portion of a rotating strand from which a helically served cover strand is being pulled and to loosely constrain the same against harmful centrifugal distortion, and a second tube substantially in coaxial alignment with the first named tube to contain the unstripped portion of the rotating strand and to loosely constrain the same against harmful centrifugal distortion, each of the tubes being diminished in internal diameter at the end thereof nearest the other tube to provide a strand supporting rim having an aperture to pass the strand and constrain the same closely against lateral displacement.

8. A device for stripping a helically served cover strand from a core strand which device comprises a tube to contain the stripped portion of a rotating strand from which a helically served cover strand is being pulled and to loosely constrain the same against harmful centrifugal distortion, and a second tube substantially in coaxial alignment with the first named tube to contain the unstripped portion of the rotating strand and to loosely constrain the same against harmful centrifugal distortion, one of the tubes the two coaxially being longitudinally adjustable with respect to the other.

9. A device for stripping a helically served cover strand from a core strand which device comprises a tube to contain the stripped portion of a rotating strand from which a helically served cover strand is being pulled and to loosely constrain the same against harmful centrifugal distortion, and a second tube substantially in coaxial alignment with the first named tube to containthe unstripped portion of the rotating strand and to loosely constrain the same against harmful centrifugal distortion, in combination with a strand supporting member positioned between the two tubes, each of the tubes and the supporting member being adjustable along the common axis of the tubes.

10 A device for stripping a helically. served cover strand from a core strand which device comprises a tube to contain the stripped portion of a rotating strand from which a helically served cover strand is being pulled and to loosely constrain the same against harmful centrifugal distortion, and a second tube substantially in coaxial alignment with the first named tube to contain the unstripped portion of the rotating strand and to loosely constrain the same against harmful centrifugal distortion, each of the tubes being externally and roundedly diminished in diameter at the end thereof nearest the other tube.

11. A device for stripping a helically served cover strand from'a core strand which device comprises a body having a bore to contain the stripped portion of a rotating strand from which a helically served cover strand is being pulled and to loosely constrain the same against harmful centrifugal distortion, and a second body having a bore substantially in coaxial alignment with the first named body having a bore to contain the unstripped portion of the rotating strand and to loosely constrain the same against harmful centrifugal distortion.

12. A device for stripping a helically served I cover strand from a core strand which device EDWARD L'HAROLD. 

